Sufio: Professional Invoices

You should just stop reading this and download it already. If your customers have even once asked for an invoice, this is the app that you need. It's super easy to use, the invoices are beautiful, you can control who gets invoices, and their service is impeccable. We use a ton of apps on Shopify, and this app, head and shoulders above others, does what it says it will and does it with flying colors.